I don't critique very often, so excuse my rustiness XD
I'll do pros and improvements:
- Celestia's anatomy looks wonderful.
- The shading is great! Her mane and tail look really well done and I can tell you put a lot of time into her.
- The composition is good and works very well.
- The background is laid out well (If you know what I mean)
Improvements: - I'm no expert at drawing water, but to me it looks a little... flat and sort of blurry. Maybe if you added some more defined ripples around Celestia and around the waterfall, and boosted the colour balance/saturation a bit, it might look less flat and fit in better as the rest of the scene is quite vibrant.
- The mist near the 'end' of the waterfall is very thick and blurred for the angle the water seems to be coming from (It basically looks like a small waterfall), maybe lower the opacity of it in places so we can see where the waterfall and the pool meet.
- When a subject is in water, the water tends to leave a 'ripply' effect near to the pbjects/things placed in the water, Its quite hard for me to explain, so I recommend getting references of people or animals in water so you can see how it reflects off someone.
Overall this piece is beautiful and visually appealing, I really like it and I think you are a wonderful artist. Next time, I would say to try and define certain things more and blur them a little less, although this looks really good, It could look even better <img src="e.deviantart.net/emoticons/h/h…" width="15" height="13" alt="" title="Heart"/> Keep it up!